1. Field of the Invention
The present invention relates to a breathing system in a four-cycle combustion engine that is used as a drive source for a working machine, for example, a small-size snowplow.
2. Description of the Prior Art
The conventional breather passage employed in the four-cycle combustion engine is formed with a breather chamber into which a blow-by gas leaking from the combustion chamber into a crank chamber through around an outer periphery of a reciprocating piston is introduced. Within this breather chamber, an oil component such as oil mists contained in the blow-by gas is separated from the blow-by gas. The separated oil component is returned to the crank chamber. On the other hand, the blow-by gas, from which the oil component has been removed, is supplied to the combustion chamber through an intake system of the combustion engine so that reburning of the blow-by gas can be carried out within the combustion chamber. See, for example, the Japanese Utility Model Registration No. 2556039.
As is well known to those skilled in the art, the blow-by gas leaking from the combustion chamber contains a substantial amount of water component. For this reason, it is desirable to remove the water component from the blow-by gas prior to the blow-by gas being supplied to the fuel intake system of the combustion engine. It has, however, been found that the prior art breather passage cannot sufficiently separate and remove the water component contained in the blow-by gas.